The present invention relates to a large-sized split-type gasket in a ring shape configuration and made of a soft material. The gasket of the invention can be used, for example, as an oil pan gasket applied between the contacting surfaces of the cylinder block and oil pan of an engine.
As is generally known, with regard to a gasket made from a sheet of an asbestos containing soft material, for example, the gasket article can be punched out at a stroke with a punch die. To reduce the pollution problem, a soft material free from asbestos is recommended. However, such asbestos-free materials have a high unit price which pushes up the cost of the gasket. As a measure taken against this rise in cost, for ring-shaped gaskets, attempts have been made to reuse the inside residue which has been punched out in ring form. Although, for example, it is known to form a gasket into a split type configuration and apply liquid gasket to the junctions during assembling, adhering the sections with a lower contact pressure allows leaks to arise easily, and is also troublesome, increasing the number of manhours required for this job.
Although the technology to connect a set of split gaskets through a piece which has a bolt hole and is formed with a different material is also commonly known, a combination of different materials creates special problems such as the selection of gasket materials and thickness, control of contact pressure and clamping force of bolts, etc., and the presence of connecting areas on both sides of the piece leads to the problem of many leaking places.